4 ms·

If you're matching on a sealed type, you do get a warning.

• lmm 6y ago
  Right - like I said, if it's "closed" you get a warning, but if it's "open" it's silently accepted and fails at runtime.
  • pkolaczk 6y ago
    The openness of match/switch over a sealed hierarchy is in another dimension - you can add more switches without changing old code. This is something that interfaces don't provide.
    • lmm 6y ago
      Visitor-style interfaces do provide that flexibility, though they're cumbersome.